code: def test_write_method(self, tmp_path):
      self._roundtrip(tmp_path, self.rgb_mode, 12.0, {"method": 6})
  
      buffer_no_args = io.BytesIO()
      hopper().save(buffer_no_args, format="WEBP")
  
      buffer_method = io.BytesIO()
      hopper().save(buffer_method, format="WEBP", method=6)
      assert buffer_no_args.getbuffer() != buffer_method.getbuffer()
  
imports: from __future__ import annotations
  import io
  import re
  import sys
  import warnings
  import pytest
  from PIL import Image, WebPImagePlugin, features
  from .helper import assert_image_equal, assert_image_similar, assert_image_similar_tofile, hopper, skip_unless_feature
label_desc: Use image node_id 6 for calling the TestFileWebp obj's underlying member method code with example usage: obj.test_write_method(tmp_path) without return types